Dressing tool for abrasive grinding wheels



Aug. 2, 1966 H. 1.. STRAUSS, JR

DRESSING TOOL FOR ABRASIVE GRINDING WHEELS Filed Oct. 8, 1965 FIG. 2

INVENTOR. IVA/Pk) 4. awa Je.

United States Patent 3,263,668 DRESSING TOOL FOR ABRASIVE GRINDING WHEELS Herry L. Strauss, Jr., 183 Sterling Road,

- Harrison, N.Y. Filed Oct. 8, 1963, Ser. No. 314,721 14 Claims. (Cl. 125-11) This invention relates to dressing tools for the dressing of abrasive grinding wheels. Such dressing is needed for either and usually both of two purposes, one being to true the wheel, and the other being to remove material clogging and thereby dulling the surface of the grinding wheel.

The grinding object of the present invention is to improve dressing tools, and more particularly such tools using a diamond dressing wheel. A more particular object is to provide a tool having two spaced dressing wheels, preferably one with coarse and the other with fine diamond grit, for simultaneous application to the grinding wheel being treated. I find that the optimum spacing of the two wheels around the periphery of the grinding wheel depends on the diameter of the grinding wheel, and in accordance with a further feature and object of the present invention, the spacing between the two dressing wheels is made adjustable.

The dressing wheels may be mounted for free rotation, in which case the dressing action depends on a direct pressure exerted by the dressing wheel against the grinding wheel. In different fashion, the dressing wheel may be operated with less pressure if rotation of the dressing wheel is restrained, and in accordance with another fea ture and object of the present invention, the tool is provided with adjustable brake means for inhibiting rotation of the dressing wheels. In extreme form, the dressing wheel could be locked against rotation, in which case it acts as a fixed dressing tool, but with a diamond surface which may be changed at intervals by releasing and turning the dressing wheel a little to present a new dressing surface.

To accomplish the foregoing general object, and other more specific objects which will hereinafter appear, my invention resides in the dressing tool elements, and their relation one to another, as are hereinafter more particularly described in the following specification. The specification is accompanied by a drawing in which:

FIG. 1 is an elevation showing the tool applied to a grinding wheel of relatively small diameter;

FIG. 2 is a similar view showing the tool modified and applied to a grinding wheel of relatively large diameter;

FIG. 3 is a plan view of the tool;

FIG. 4 is a front elevation of the same;

FIG. 5 is an end view of the same;

FIG. 6 is a fragmentary view like the upper right portion of FIG. 4, but showing a modification having a brake insert; and

FIG. 7 is a view like FIG. 6, but showing a different form of brake.

Referring to the drawing, and more particularly to FIG. 1, the dressing tool comprises a tool body 12 carrying spaced dressing wheels 14 and 1-6, the said wheels bearing simultaneously against an abrasive grinding wheel 18 to dress the same. FIG. 2 shows the same tool applied to an abrasive grinding wheel 20 of much larger diameter than the wheel 18 shown in FIG. 1. In this case it is preferred to space the dressing wheels 14 and 16 further apart, and adjustment of the spacing is afforded by the tool body 12.

The wheels 14 and 16 are preferably diamond dressing Wheels, the wheel 14 having relatively coarse diamond grit, and the wheel 16 having relatively fine diamond grit.

The tool is so positioned, relative to the direction of rotation of the grinding wheel 18 or 20, that the coarse wheel 14 engages the grinding wheel ahead of the fine wheel 16.

A preferred form of tool may be described in greater detatil with reference to FIGS. 3, 4 and 5 of the drawing. The tool comprises a cylindrical shank 12 carrying a head 24. There is a first pair of arms 26 projecting from the head 24, and a first diamond dressing wheel 14 carried between the outer ends of the arms 26. A second pair of arms 30 projects from the head 24 at an angle to the first pair of arms 26. A second diamond dressing wheel 16 is rotatably carried between the outer ends of the second pair of arms 30.

The wheel 14 contains relatively coarse diamond grit, and the wheel 16 contains relatively fine diamond. grit. As an example, but not in limitation of the invention, the Wheel 14 may have #20 grit, and the wheel 16 may have #60 grit. The particular wheels shown have a diameter of inch and a width of /2 inch, but these dimensions are given merely by way of example, and not in limitation. The wheel 14 is carried on a shaft of trunnions 34, and wheel 16 is similarly carried on a shaft or trunnions 36. The diamond grit is bound in a metal matrix, and the matrix may be made of sintered metal. The metal particles may be hard metal such as tungsten carbide or chromium boride, or they may be soft metal such as alloys of nickel bearing brasses or copper alloys. These are mentioned merely as examples.

The entire body of the wheel may be made of sintered metal with diamond grit, as described, or only the peripheral portion of the wheel, around a center or core 38. The shaft 34 may be fixed in the wheel, or when intended to be freely rotatable the shaft may be free of the wheel. For reasons discussed later, I prefer to use a shaft or trunnions which are fixed to the wheel.

The angle between the first pair of arms 26 and the second pair of arms 30 may be varied in order to adjust the spacing between the wheels. In the present case the arms 26 are mounted in position on head 24 by means of a cap screw 40, the end 42 of which is threadedly received in the adjacent arm 26. The arms may be alike except that one has a clearance hole, and the other a thread. Similarly the arms 30 are mounted in position by means of a cap screw 44, the end 416 of which is threadedly received in the adjacent arm 30. It will be seen that by loosening the screws the angular relation of the arms may be changed, and that by then tightening the screws, the arms will be held in desired angular relation.

However, it is preferred to provide additional lock means to more securely lock the arms in their adjusted position. In the present case the inwardly stepped or narrowed portion 50 of the head 24 is slotted between the arms, as shown at 52. A threaded hole 54 extends in the same direction as the slot 52. A lock screw 56 is received in hole 54. This lock screw is given a somewhat oversized thread, or it may be given a slight taper. In any case it acts as a wedge for slightly spreading apart the sides of the part 50 between the arms.

For change of spacing, the lock screw 56 is backed out or even removed. The screws 40 and 44 are slightly loosened to adjust the arms 26 and 30 to desired angular relation. The screws 40 and 44 are then tightened, Whereupon the lock screw 56 is screwed into its receptive hole as far as possible, thereby slightly spreading the split portion 50 of the head, and thereby additionally locking the arms in their adjusted position.

As so far described it may be assumed that the dressing wheels are freely rotatable. In such case the cylindrical shank 12 of the tool is mounted in a holder or attachment (not shown) designed to force the tool against the grinding wheel with considerable force. If the wheels are freely 3 rotatable on fixed shafts 34 and 36, the arms 26 and 30 are preferably provided with set screws 58, the latter serving to hold the shaft against axial movement as well as against rotation. If the wheels have trunnions which are to be freely rotatable, the set screws 58 are not used.

In a wholly different mode of operation, the set screws could be used to lock the wheels against rotation, the wheels then acting as fixed dressing tools. In such case each wheel may occasionally be freed, turned somewhat, and again locked, in order to present a new part of the dressing wheel for use as a fixed dressing tool.

However, I do not recommend such action, and instead I recommend that the dressing wheels be rotatable, but with a braking action to inhibit free rotation. In FIG. 6 the arms 126 correspond to the arms 26 shown in FIG. 4, but have been enlarged somewhat at the end to receive a brake shoe 60, the pressure of the latter being adjustable by means of a pressure screw 62. The outer wall of the shoe 60 is recessed somewhat to receive the inner end of screw 62, thereby holding the shoe against axial movement. The shoe is desirably made of nylon. The screw 62 may be tightened from time to time as the nylon shoe is worn, and the shoe is readily replaced when completely worn.

Another form of brake is shown in FIG. 7, in which thearm 226 corresponds to the arm 26 in FIG. 4. The arm 226 is split at 64, 66 so that the bearing hole 68 may be contracted by means of a brake screw 70. The hearing hole may be applied directly to the shaft 34, or a bushing 72 may be used. The bushing may be made of nylon or other suitable bearing material, and may be split as shown at 74 to respond more readily to the tightening action of the .brake screw 70.

By clamping either brake very tightly the brake could be used to lock the shaft against rotation, should it be desired to use the wheels as fixed dressing tools, but in preferred operation the rotation of the diamond whee s is merely inhibited or braked, rather than prevented altogether.

The abrasive grinding wheel 18 and 20 shown in FIGS. 1 and 2 may be made of silicon carbide, aluminum oxide or other such abrasive material. The dressing wheels preferably are diamond bearing wheels. For very coarse dressing, the diamond wheel could carry diamond pieces rather than grit, and in such case the pieces would be localized to the peripheral surface of the wheel.

It is believed that the construction and method of use of my improved dressing tool, as well as the advantages of the same, will be apparent from the foregoing detailed description. It will also be apparent that while I have shown and described the tool in several preferred forms, changes may be made without departing from the scope of the invention, as sought to be defined in the following claims.

I claim:

1. A diamond dressing tool for dressing abrasive grinding wheels, said tool comprising a tool body carrying two spaced diamond dressing wheels on parallel shafts for simultaneous application to the same surface of a grinding wheel, one of said wheels having relatively coarse diamond grit and the other having relatively fine diamond grit, and fixed adjustable brake means localized at each wheel to inhibit rotation of said dressing wheels.

2. A diamond dressing tool for dressing abrasive grind ing wheels, said tool comprising a tool body carrying two spaced diamond dressing wheels on parallel shafts, one of said wheels having relatively coarse diamond grit and the other having relatively fine diamond grit, means whereby the spacing between the parallelaxes of said dressing wheels may be adjusted to a desired amount, and fixed adjustable brake means to inhibit rotation of said dressing Wheels.

3. A dressing tool for dressing abrasive grinding wheels, said tool comprising a tool body carrying two spaced dressing wheels on parallel shafts for simultaneous application to the same surface of a grinding wheel, one of said wheels being relatively coarse and the other being relatively fine, means whereby the spacing between the parallel axes of said dressing wheels may be adjusted to a desired spacing, and fixed adjustable brake means to inhibit rotation of said dressing wheels.

4. A dressing tool for dressing abrasive grinding wheels, said tool comprising a shank carrying a head, a first arm pivoted on and projecting from said head, a first dressing wheel rotatably carried at the outer end of said arm, a second arm pivoted on and projecting from said head at an angle to the first arm, a second dressing wheel rotatably carried at the outer end of said second arm, said first and second wheels being carried on parallel shafts, said first and second arms being carried on pivots which are parallel to one another and to the shafts of the wheels, whereby the angle between said first and second arms may be varied in order to adjust the spacing between said first and second wheels, and lock means to lock said arms in adjusted position.

5. A dressing tool for dressing abrasive grinding wheels, said tool comprising a shank carrying a head, a first arm pivoted on and projecting from said head, a first dressing wheel rotatably carried at the outer end of said arm, a second arm pivoted on and projecting from said head at an angle to the first arm, a second dressing wheel rotatably carried at the outer end of said second arm, brake means on said arms to inhibit rotation of said wheels, said first and second wheels being carried on par-allel shafts, said first and second arms being carried on pivots which are parallel to one another and to the shafts of the wheels, whereby the angle between said first and second arms may be varied in order to adjust the spacing between said first and second wheels, and lock means to lock said arms in adjusted position.

6. A diamond dressing tool for dressing abrasive grinding wheels, said tool comprising a shank carrying a head, a first arm projecting from said head, a first diamond dressing wheel rotatably carried at the outer end of said first arm, a second arm projecting from said head at an angle to the first arm, a second diamond dressing wheel rotatably carried at the outer end of said second arm, said first and second wheels being carried on parallel shafts which are transverse of the arms and the shank, and fixed adjustable brake means on said arms to inhibit rotation of said wheels, one of said wheels having relatively coarse diamond grit and the other having relatively fine diamond grit.

7. A diamond dressing tool for dressing abrasive grinding wheels, said tool comprising a shank carrying a head, a first arm pivoted on and projecting from said head, a first diamond dressing wheel rotatably carried at the outer end of said first arm, a second arm pivoted on and projecting from said head at an angle to the first arm, a second diamond dressing wheel rotatably carried at the outer end of said second arm, said first and second wheels being carried on parallel shafts, said first and second arms being carried on pivots which are parallel to one another and to the shafts of the wheels, whereby the angle between said first and second arms may be varied in order to adjust the spacing between said first and second Wheels, and lock means to lock said arms in adjusted position, one of said wheels having relatively coarse diamond grit and the other having relatively fine diamond grit.

j 8. A diamond dressing tool for dressing abrasive grinding'wheels, said tool comprising a shank carrying a head, a first arm pivoted on and projecting from said head, a first diamond dressing wheel rotatably carried at the outer end of said first arm, a second arm pivoted on and projecting from said head at an angle to the first arm, a second diamond dressing wheel rotatably carried at the outer end of said second arm, brake means on said arms to inhibit rotation of said wheels, said first and second wheels being carried on parallel shafts, said first and second arms being carried on pivots which are parallel to one another and to the shafts of the wheels, whereby the angle between said first and second arms may be varied in order to adjust the spacing between said first and second wheels, and lock means to lock said arms in adjusted position, one of said wheels having relatively coarse diamond grit and the other having relatively fine diamond grit.

9. A diamond dressing tool for dressing abrasive grinding wheels, said tool comprising a shank carrying a head, a first pair of collateral arms projecting from said head, a first diamond dressing wheel rotatably carried between the outer ends of said arms, a second pair of collateral arms projecting from said head at an angle to the first pair, a second diamond dressing wheel rotatably carried between the outer ends of said second pair of arms, said first and second wheels being carried on parallel shafts which are transverse to the arms and shank, and fixed adjustable brake means on said arms to inhibit rotation of said wheels, one of said Wheels having relatively coarse diamond grit and the other having relatively fine diamond grit.

10. A diamond dressing tool for dressing abrasive grinding wheels, said tool comprising a shank carrying a head, a first pair of collateral arms pivoted on and projecting from said head, a first diamond dressing wheel rotatably carried between the outer ends of said arms, a second pair of collateral arms pivoted on and projecting from said head at an angle to the first pair, a second diamond dressing wheel rotatably carried between the outer ends of said second pair of arms, said first and second wheels being carried on parallel shafts, said first and second pairs of collateral arms being carried on pivots which are parallel to one another and to the shafts of the wheels, whereby the angle between said first and second pairs of arms may be varied in order to adjust the spacing between said first and second wheels, and lock means to lock said arms in adjusted position, one of said wheels having relatively coarse diamond grit and the other having relatively fine diamond grit.

11. A diamond dressing tool for dressing abrasive grinding wheels, said tool comprising a shank carrying a head, a first pair of collateral arms pivoted on and projecting from said head, a first diamond dressing wheel rotatably carried between the outer ends of said arms, a second pair of collateral arms pivoted on and projecting from said head at an angle to the first pair, a second diamond dressing wheel rotatably carried between the outer ends of said second pair of arms, brake means on said arms to inhibit rotation of said wheels, said first and second wheels being carried on parallel shafts, said first and second pairs of collateral arms being carried on pivots which are parallel to one another and to the shafts of the wheels, whereby the angle between said first and second pairs of arms may be varied in order to adjust the spacing between said first and second wheels, and lock means to lock said arms in adjusted position, one of said wheels having relatively coarse diamond grit and the other having relatively fine diamond grit.

12. A diamond dressing tool for dressing abrasive grinding wheels, said tool comprising a tool body carrying two spaced parallel shafts which cannot be turned out of parallelism, diamond dressing wheels rotatable on said parallel shafts for simultaneous application to the peripheral surface of a grinding wheel with the said shafts being parallel to the axis of the said grinding wheel, one of said wheels having relatively coarse diamond grit and the other having relatively fine diamond grit, and means whereby the spacing between the parallel axes of said dressing wheels may be adjusted to a desired amount.

[13. A dressing tool for dressing abrasive grinding wheels, said tool comprising a tool body carrying two spaced parallel shafts which cannot :be turned out of parallelism, two dressing wheels rotatable on said parallel shafts for simultaneous application to the peripheral surface of a grinding wheel, with the said shafts being parallel to the axis of the said grinding wheel, one of said wheels being relatively coarse and the other being relatively fine, and means whereby the spacing between the parallel axes of said dressing wheels may be adjusted to a desired spacing.

14. A dressing tool for dressing abrasive grinding wheels, said tool comprising a shank carrying a head, a first arm projecting from said head, a first dressing wheel rotatably carried at the outer end of said arm, a second arm projecting from said head at an angle to the first arm, a second dressing wheel rotatably carried at the outer end of said second arm, said first and second wheels being carried on parallel shafts which are transverse of the arms and the shank, and which shafts cannot be turned out of parallelism, said wheels 'being designed for simultaneous application to the peripheral surface of a grinding wheel with the said shafts then being parallel to the axis of the grinding Wheel, brake means on each of said arms to inhibit rotation of said wheels, and means including an adjust-able screw to fix the braking action of each of the brake means.

References Cited by the Examiner UNITED STATES PATENTS 602,106 4/ 1-898 Roberts -37 1,429,317 9/1922 Bagi 51-2621 1 1,443,504 1/ 1923 Roberts et al. 125--37 2,897,810 8/1959 DAmato 12S11.2 3,046,967 7/ 1 962 Balsiger 125-1 1.2

FOREIGN PATENTS 164,263 6/1921 Great Britain.

r HAROLD D. WHITEHEAD, Primary Examiner. 

1. A DIAMOND DRESSING TOOL FOR DRESSING ABRASIVE GRINDING WHEELS, SAID TOOL COMPRISING A TOOL BODY CARRYING TWO SPACED DIAMOND DRESSING WHEELS ON PARALLEL SHAFTS FOR SIMULTANEOUSE APPLICATION TO THE SAME SURFACE OF A GRINDING WHEEL, ONE OF SAID WHEELS HAVING RELATIVELY COARSE 